5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 * Copyright 2000,2001,2002 The FreeRADIUS server project
20 * Copyright 2001,2002 Google, Inc.
21 * Copyright 2005 TRI-D Systems, Inc.
25 * STRONG WARNING SECTION:
27 * ANSI X9.9 has been withdrawn as a standard, due to the weakness of DES.
28 * An attacker can learn the token's secret by observing two
29 * challenge/response pairs. See ANSI document X9 TG-24-1999
30 * <URL:http://www.x9.org/docs/TG24_1999.pdf>.
32 * Please read the accompanying docs.
36 * TODO: support setting multiple auth-types in authorize()
37 * TODO: support other than ILP32 (for State)
43 #include <sys/types.h>
48 #include <netinet/in.h> /* htonl(), ntohl() */
52 #include <freeradius-devel/modules.h>
55 static const char rcsid[] = "$Id$";
58 static unsigned char hmac_key[16]; /* to protect State attribute */
59 static int ninstance = 0; /* #instances, for global init */
61 /* A mapping of configuration file names to internal variables. */
62 static const CONF_PARSER module_config[] = {
63 { "pwdfile", PW_TYPE_STRING_PTR, offsetof(otp_option_t, pwdfile),
65 { "lsmd_rp", PW_TYPE_STRING_PTR, offsetof(otp_option_t, lsmd_rp),
67 { "challenge_prompt", PW_TYPE_STRING_PTR,offsetof(otp_option_t, chal_prompt),
68 NULL, OTP_CHALLENGE_PROMPT },
69 { "challenge_length", PW_TYPE_INTEGER, offsetof(otp_option_t, chal_len),
71 { "challenge_delay", PW_TYPE_INTEGER, offsetof(otp_option_t, chal_delay),
73 { "softfail", PW_TYPE_INTEGER, offsetof(otp_option_t, softfail),
75 { "hardfail", PW_TYPE_INTEGER, offsetof(otp_option_t, hardfail),
77 { "allow_sync", PW_TYPE_BOOLEAN, offsetof(otp_option_t, allow_sync),
79 { "fast_sync", PW_TYPE_BOOLEAN, offsetof(otp_option_t, fast_sync),
81 { "allow_async", PW_TYPE_BOOLEAN, offsetof(otp_option_t, allow_async),
83 { "challenge_req", PW_TYPE_STRING_PTR, offsetof(otp_option_t, chal_req),
84 NULL, OTP_CHALLENGE_REQ },
85 { "resync_req", PW_TYPE_STRING_PTR, offsetof(otp_option_t, resync_req),
86 NULL, OTP_RESYNC_REQ },
87 { "prepend_pin", PW_TYPE_BOOLEAN, offsetof(otp_option_t, prepend_pin),
89 { "ewindow_size", PW_TYPE_INTEGER, offsetof(otp_option_t, ewindow_size),
91 { "rwindow_size", PW_TYPE_INTEGER, offsetof(otp_option_t, rwindow_size),
93 { "rwindow_delay", PW_TYPE_INTEGER, offsetof(otp_option_t, rwindow_delay),
95 { "mschapv2_mppe", PW_TYPE_INTEGER,
96 offsetof(otp_option_t, mschapv2_mppe_policy), NULL, "2" },
97 { "mschapv2_mppe_bits", PW_TYPE_INTEGER,
98 offsetof(otp_option_t, mschapv2_mppe_types), NULL, "2" },
99 { "mschap_mppe", PW_TYPE_INTEGER,
100 offsetof(otp_option_t, mschap_mppe_policy), NULL, "2" },
101 { "mschap_mppe_bits", PW_TYPE_INTEGER,
102 offsetof(otp_option_t, mschap_mppe_types), NULL, "2" },
104 { "debug", PW_TYPE_BOOLEAN, offsetof(otp_option_t, debug),
107 { NULL, -1, 0, NULL, NULL } /* end the list */
111 /* transform otp_pw_valid() return code into an rlm return code */
116 case OTP_RC_OK: return RLM_MODULE_OK;
117 case OTP_RC_USER_UNKNOWN: return RLM_MODULE_REJECT;
118 case OTP_RC_AUTHINFO_UNAVAIL: return RLM_MODULE_REJECT;
119 case OTP_RC_AUTH_ERR: return RLM_MODULE_REJECT;
120 case OTP_RC_MAXTRIES: return RLM_MODULE_USERLOCK;
121 case OTP_RC_SERVICE_ERR: return RLM_MODULE_FAIL;
122 default: return RLM_MODULE_FAIL;
127 /* per-instance initialization */
129 otp_instantiate(CONF_SECTION *conf, void **instance)
131 const char *log_prefix = OTP_MODULE_NAME;
135 /* Set up a storage area for instance data. */
136 opt = rad_malloc(sizeof(*opt));
137 (void) memset(opt, 0, sizeof(*opt));
139 /* If the configuration parameters can't be parsed, then fail. */
140 if (cf_section_parse(conf, opt, module_config) < 0) {
145 /* Onetime initialization. */
147 /* Generate a random key, used to protect the State attribute. */
148 if (otp_get_random(-1, hmac_key, sizeof(hmac_key), log_prefix) == -1) {
149 otp_log(OTP_LOG_ERR, "%s: %s: failed to obtain random data for hmac_key",
150 log_prefix, __func__);
155 /* Initialize the passcode encoding/checking functions. */
159 * Don't do this again.
160 * Only the main thread instantiates and detaches instances,
161 * so this does not need mutex protection.
166 /* Verify ranges for those vars that are limited. */
167 if ((opt->chal_len < 5) || (opt->chal_len > OTP_MAX_CHALLENGE_LEN)) {
170 "%s: %s: invalid challenge_length, range 5-%d, using default of 6",
171 log_prefix, __func__, OTP_MAX_CHALLENGE_LEN);
174 /* Enforce a single "%" sequence, which must be "%s" */
175 p = strchr(opt->chal_prompt, '%');
176 if ((p == NULL) || (p != strrchr(opt->chal_prompt, '%')) ||
178 free(opt->chal_prompt);
179 opt->chal_prompt = strdup(OTP_CHALLENGE_PROMPT);
181 "%s: %s: invalid challenge_prompt, using default of \"%s\"",
182 log_prefix, __func__, OTP_CHALLENGE_PROMPT);
185 if (opt->softfail < 0) {
187 otp_log(OTP_LOG_ERR, "%s: %s: softfail must be at least 1 "
188 "(or 0 == infinite), using default of 5",
189 log_prefix, __func__);
192 if (opt->hardfail < 0) {
194 otp_log(OTP_LOG_ERR, "%s: %s: hardfail must be at least 1 "
195 "(or 0 == infinite), using default of 0",
196 log_prefix, __func__);
199 if (!opt->hardfail && opt->hardfail <= opt->softfail) {
201 * This is noise if the admin leaves softfail alone, so it gets
202 * the default value of 5, and sets hardfail <= to that ... but
203 * in practice that will never happen. Anyway, it is easily
204 * overcome with a softfail setting of 0.
206 * This is because we can't tell the difference between a default
207 * [softfail] value and an admin-configured one.
209 otp_log(OTP_LOG_ERR, "%s: %s: hardfail (%d) is less than softfail (%d), "
210 "effectively disabling softfail",
211 log_prefix, __func__, opt->hardfail, opt->softfail);
214 if (opt->fast_sync && !opt->allow_sync) {
216 otp_log(OTP_LOG_ERR, "%s: %s: fast_sync is yes, but allow_sync is no; "
217 "disabling fast_sync",
218 log_prefix, __func__);
221 if (!opt->allow_sync && !opt->allow_async) {
223 "%s: %s: at least one of {allow_async, allow_sync} must be set",
224 log_prefix, __func__);
229 if ((opt->ewindow_size > OTP_MAX_EWINDOW_SIZE) ||
230 (opt->ewindow_size < 0)) {
231 opt->ewindow_size = 0;
232 otp_log(OTP_LOG_ERR, "%s: %s: max ewindow_size is %d, using default of 0",
233 log_prefix, __func__, OTP_MAX_EWINDOW_SIZE);
236 if (opt->rwindow_size && (opt->rwindow_size < opt->ewindow_size)) {
237 opt->rwindow_size = 0;
238 otp_log(OTP_LOG_ERR, "%s: %s: rwindow_size must be at least as large as "
239 "ewindow_size, using default of 0",
240 log_prefix, __func__);
243 if (opt->rwindow_size && !opt->rwindow_delay) {
244 opt->rwindow_size = 0;
245 otp_log(OTP_LOG_ERR, "%s: %s: rwindow_size is non-zero, "
246 "but rwindow_delay is zero; disabling rwindow",
247 log_prefix, __func__);
250 if ((opt->mschapv2_mppe_policy > 2) || (opt->mschapv2_mppe_policy < 0)) {
251 opt->mschapv2_mppe_policy = 2;
253 "%s: %s: invalid value for mschapv2_mppe, using default of 2",
254 log_prefix, __func__);
257 if ((opt->mschapv2_mppe_types > 2) || (opt->mschapv2_mppe_types < 0)) {
258 opt->mschapv2_mppe_types = 2;
260 "%s: %s: invalid value for mschapv2_mppe_bits, using default of 2",
261 log_prefix, __func__);
264 if ((opt->mschap_mppe_policy > 2) || (opt->mschap_mppe_policy < 0)) {
265 opt->mschap_mppe_policy = 2;
267 "%s: %s: invalid value for mschap_mppe, using default of 2",
268 log_prefix, __func__);
271 if (opt->mschap_mppe_types != 2) {
272 opt->mschap_mppe_types = 2;
274 "%s: %s: invalid value for mschap_mppe_bits, using default of 2",
275 log_prefix, __func__);
278 /* set the instance name (for use with authorize()) */
279 opt->name = cf_section_name2(conf);
281 opt->name = cf_section_name1(conf);
283 otp_log(OTP_LOG_CRIT, "%s: %s: no instance name (this can't happen)",
284 log_prefix, __func__);
289 /* set debug opt for portable debug output (see DEBUG definition) */
298 /* Generate a challenge to be presented to the user. */
300 otp_authorize(void *instance, REQUEST *request)
302 otp_option_t *inst = (otp_option_t *) instance;
303 const char *log_prefix = OTP_MODULE_NAME;
305 char challenge[OTP_MAX_CHALLENGE_LEN + 1]; /* +1 for '\0' terminator */
308 int32_t sflags = 0; /* flags for state */
310 struct otp_pwe_cmp_t data = {
316 /* Early exit if Auth-Type != inst->name */
321 if ((vp = pairfind(request->config_items, PW_AUTHTYPE)) != NULL) {
323 if (strcmp(vp->vp_strvalue, inst->name))
324 return RLM_MODULE_NOOP;
328 /* The State attribute will be present if this is a response. */
329 if (pairfind(request->packet->vps, PW_STATE) != NULL) {
330 DEBUG("rlm_otp: autz: Found response to Access-Challenge");
331 return RLM_MODULE_OK;
334 /* User-Name attribute required. */
335 if (!request->username) {
336 otp_log(OTP_LOG_AUTH,
337 "%s: %s: Attribute \"User-Name\" required for authentication.",
338 log_prefix, __func__);
339 return RLM_MODULE_INVALID;
342 if ((data.pwattr = otp_pwe_present(request, log_prefix)) == 0) {
343 otp_log(OTP_LOG_AUTH, "%s: %s: Attribute \"User-Password\" "
344 "or equivalent required for authentication.",
345 log_prefix, __func__);
346 return RLM_MODULE_INVALID;
349 /* fast_sync mode (challenge only if requested) */
350 if (inst->fast_sync) {
351 if ((!otp_pwe_cmp(&data, inst->resync_req, log_prefix) &&
352 /* Set a bit indicating resync */ (sflags |= htonl(1))) ||
353 !otp_pwe_cmp(&data, inst->chal_req, log_prefix)) {
355 * Generate a challenge if requested. Note that we do this
356 * even if configuration doesn't allow async mode.
358 DEBUG("rlm_otp: autz: fast_sync challenge requested");
362 /* Otherwise, this is the token sync response. */
363 if (!auth_type_found)
364 pairadd(&request->config_items, pairmake("Auth-Type", "otp", T_OP_EQ));
365 return RLM_MODULE_OK;
368 } /* if (fast_sync && card supports sync mode) */
371 /* Set the resync bit by default if the user can't choose. */
372 if (!inst->fast_sync)
375 /* Generate a random challenge. */
376 if (otp_async_challenge(-1, challenge, inst->chal_len, log_prefix) == -1) {
377 otp_log(OTP_LOG_ERR, "%s: %s: failed to obtain random challenge",
378 log_prefix, __func__);
379 return RLM_MODULE_FAIL;
383 * Create the State attribute, which will be returned to us along with
384 * the response. We will need this to verify the response. It must
385 * be hmac protected to prevent insertion of arbitrary State by an
386 * inside attacker. If we won't actually use the State (server config
387 * doesn't allow async), we just use a trivial State. We always create
388 * at least a trivial State, so otp_authorize() can quickly pass on to
389 * otp_authenticate().
391 if (inst->allow_async) {
392 time_t now = time(NULL);
394 if (sizeof(now) != 4 || sizeof(long) != 4) {
395 otp_log(OTP_LOG_ERR, "%s: %s: only ILP32 arch is supported",
396 log_prefix, __func__);
397 return RLM_MODULE_FAIL;
401 if (otp_gen_state(&state, NULL, challenge, inst->chal_len, sflags,
402 now, hmac_key) != 0) {
403 otp_log(OTP_LOG_ERR, "%s: %s: failed to generate state",
404 log_prefix, __func__);
405 return RLM_MODULE_FAIL;
408 state = rad_malloc(5);
409 (void) sprintf(state, "0x00");
411 pairadd(&request->reply->vps, pairmake("State", state, T_OP_EQ));
414 /* Add the challenge to the reply. */
416 char *u_challenge; /* challenge with addt'l presentation text */
418 u_challenge = rad_malloc(strlen(inst->chal_prompt) +
419 OTP_MAX_CHALLENGE_LEN + 1);
421 (void) sprintf(u_challenge, inst->chal_prompt, challenge);
422 pairadd(&request->reply->vps,
423 pairmake("Reply-Message", u_challenge, T_OP_EQ));
428 * Mark the packet as an Access-Challenge packet.
429 * The server will take care of sending it to the user.
431 request->reply->code = PW_ACCESS_CHALLENGE;
432 DEBUG("rlm_otp: Sending Access-Challenge.");
434 /* TODO: support config-specific auth-type */
435 if (!auth_type_found)
436 pairadd(&request->config_items, pairmake("Auth-Type", "otp", T_OP_EQ));
437 return RLM_MODULE_HANDLED;
441 /* Verify the response entered by the user. */
443 otp_authenticate(void *instance, REQUEST *request)
445 otp_option_t *inst = (otp_option_t *) instance;
446 const char *log_prefix = OTP_MODULE_NAME;
450 int resync = 0; /* resync flag for async mode */
452 unsigned char challenge[OTP_MAX_CHALLENGE_LEN]; /* cf. authorize() */
453 VALUE_PAIR *add_vps = NULL;
455 struct otp_pwe_cmp_t data = {
458 .returned_vps = &add_vps
461 /* User-Name attribute required. */
462 if (!request->username) {
463 otp_log(OTP_LOG_AUTH,
464 "%s: %s: Attribute \"User-Name\" required for authentication.",
465 log_prefix, __func__);
466 return RLM_MODULE_INVALID;
468 username = request->username->vp_strvalue;
470 if ((data.pwattr = otp_pwe_present(request, log_prefix)) == 0) {
471 otp_log(OTP_LOG_AUTH, "%s: %s: Attribute \"User-Password\" "
472 "or equivalent required for authentication.",
473 log_prefix, __func__);
474 return RLM_MODULE_INVALID;
477 /* Add a message to the auth log. */
478 pairadd(&request->packet->vps, pairmake("Module-Failure-Message",
479 OTP_MODULE_NAME, T_OP_EQ));
480 pairadd(&request->packet->vps, pairmake("Module-Success-Message",
481 OTP_MODULE_NAME, T_OP_EQ));
483 /* Retrieve the challenge (from State attribute). */
486 unsigned char *state;
487 int32_t sflags = 0; /* state flags */
488 int32_t then; /* state timestamp */
490 if ((vp = pairfind(request->packet->vps, PW_STATE)) != NULL) {
491 int e_length = inst->chal_len;
493 /* Extend expected length if state should have been protected. */
494 if (inst->allow_async)
495 e_length += 4 + 4 + 16; /* sflags + time + hmac */
497 if (vp->length != e_length) {
498 otp_log(OTP_LOG_AUTH, "%s: %s: bad state for [%s]: length",
499 log_prefix, __func__, username);
500 return RLM_MODULE_INVALID;
503 if (inst->allow_async) {
504 /* Verify the state. */
505 (void) memcpy(challenge, vp->vp_strvalue, inst->chal_len);
506 (void) memcpy(&sflags, vp->vp_strvalue + inst->chal_len, 4);
507 (void) memcpy(&then, vp->vp_strvalue + inst->chal_len + 4, 4);
508 if (otp_gen_state(NULL, &state, challenge, inst->chal_len,
509 sflags, then, hmac_key) != 0) {
510 otp_log(OTP_LOG_ERR, "%s: %s: failed to generate state",
511 log_prefix, __func__);
512 return RLM_MODULE_FAIL;
514 if (memcmp(state, vp->vp_strvalue, vp->length)) {
515 otp_log(OTP_LOG_AUTH, "%s: %s: bad state for [%s]: hmac",
516 log_prefix, __func__, username);
518 return RLM_MODULE_REJECT;
522 /* State is valid, but check expiry. */
524 if (time(NULL) - then > inst->chal_delay) {
525 otp_log(OTP_LOG_AUTH, "%s: %s: bad state for [%s]: expired",
526 log_prefix, __func__, username);
527 return RLM_MODULE_REJECT;
529 resync = ntohl(sflags) & 1;
530 } /* if (State should have been protected) */
531 } /* if (State present) */
535 rc = otprc2rlmrc(otp_pw_valid(username, challenge, NULL, resync, inst,
536 otp_pwe_cmp, &data, log_prefix));
538 /* Handle any vps returned from otp_pwe_cmp(). */
539 if (rc == RLM_MODULE_OK) {
540 pairadd(&request->reply->vps, add_vps);
548 /* per-instance destruction */
550 otp_detach(void *instance)
552 otp_option_t *inst = (otp_option_t *) instance;
556 free(inst->chal_prompt);
557 free(inst->chal_req);
558 free(inst->resync_req);
561 * Only the main thread instantiates and detaches instances,
562 * so this does not need mutex protection.
564 if (--ninstance == 0)
565 memset(hmac_key, 0, sizeof(hmac_key));
572 * If the module needs to temporarily modify it's instantiation
573 * data, the type should be changed to RLM_TYPE_THREAD_UNSAFE.
574 * The server will then take care of ensuring that the module
575 * is single-threaded.
580 RLM_TYPE_THREAD_SAFE, /* type */
581 otp_instantiate, /* instantiation */
582 otp_detach, /* detach */
584 otp_authenticate, /* authentication */
585 otp_authorize, /* authorization */
586 NULL, /* preaccounting */
587 NULL, /* accounting */
588 NULL, /* checksimul */
589 NULL, /* pre-proxy */
590 NULL, /* post-proxy */